diff --git a/regression_var.sh b/regression_var.sh
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+++ b/regression_var.sh
@@ -0,0 +1,245 @@
+#!/bin/sh
+# It is now possible to run all regression tests (except RTMA) using the hybrid ensemble option with
+# internally generated random ensemble perturbations.  No script changes are required.
+#  To run with hybrid ensemble option on, change HYBENS_GLOBAL and/or HYBENS_REGIONAL from "false" to "true".
+#  These are located at the end of this script.
+
+if [ "$#" = 7 ] ; then
+  export basedir=$1
+  export builddir=$2
+  export gsisrc=$3
+  export gsiexec_updat=$4
+  export enkfexec_updat=$5
+  export gsiexec_contrl=$6
+  export enkfexec_contrl=$7
+  export fixgsi="$gsisrc/fix"
+  export scripts="$gsisrc/regression"
+  export ush="$gsisrc/ush"
+  export cmaketest="true"
+  export clean="false"
+  dir_root="${builddir%/*}"
+  export ptmpName="${dir_root##*/}"
+else
+  # Name of the branch being tested
+  updat="mine"
+  contrl="develop"
+  export cmaketest="false"
+  export clean="false"
+  export ptmpName=""
+fi
+
+# Determine the machine
+if [[ -d /glade ]]; then # Cheyenne
+  export machine="Cheyenne"
+elif [[ -d /scratch1 ]]; then # Hera
+  export machine="Hera"
+elif [[ -d /mnt/lfs4 || -d /jetmon || -d /mnt/lfs1 ]]; then # Jet
+  export machine="Jet"
+elif [[ -d /discover ]]; then # NCCS Discover
+  export machine="Discover"
+elif [[ -d /sw/gaea ]]; then # Gaea
+  export machine="Gaea"
+elif [[ -d /data/prod ]]; then # S4
+  export machine="S4"
+elif [[ -d /work ]]; then # Orion
+  export machine="Orion"
+elif [[ -d /lfs/h2 ]]; then # wcoss2
+  export machine="wcoss2"
+fi
+echo "Running Regression Tests on '$machine'";
+
+case $machine in
+  Cheyenne)
+    export queue="economy"
+    export noscrub="/glade/scratch/$LOGNAME"
+    export group="global"
+    if [[ "$cmaketest" = "false" ]]; then
+      export basedir="/glade/scratch/$LOGNAME/gsi"
+    fi
+    export ptmp="/glade/scratch/$LOGNAME/$ptmpName"
+
+    export casesdir="/glade/p/ral/jntp/tools/CASES"
+
+    export check_resource="no"
+    export accnt="p48503002"
+  ;;
+  wcoss2)
+      export local_or_default="${local_or_default:-/lfs/h2/emc/da/noscrub/$LOGNAME}"
+      if [ -d $local_or_default ]; then
+          export noscrub="$local_or_default/noscrub"
+      elif [ -d /lfs/h2/emc/global/noscrub/$LOGNAME ]; then
+          export noscrub="/lfs/h2/emc/global/noscrub/$LOGNAME/noscrub"
+      fi
+
+      export queue="${queue:-dev}"
+      export group="${group:-global}"
+      if [[ "$cmaketest" = "false" ]]; then
+	  export basedir="/lfs/h2/emc/da/noscrub/$LOGNAME/gsi"
+      fi
+      export ptmp="${ptmp:-/lfs/h2/emc/ptmp/$LOGNAME/$ptmpName}"
+
+      export casesdir="/lfs/h2/emc/da/noscrub/russ.treadon/CASES/regtest"
+
+      export check_resource="no"
+      export accnt="${accnt:-GFS-DEV}"
+  ;;      
+  Orion)
+      export local_or_default="${local_or_default:-/work/noaa/da/$LOGNAME}"
+      if [ -d $local_or_default ]; then
+          export noscrub="$local_or_default/noscrub"
+      elif [ -d /work/noaa/global/$LOGNAME ]; then
+	  export noscrub="/work/noaa/global/$LOGNAME/noscrub"
+      fi
+
+      export queue="${queue:-batch}"
+      export group="${group:-global}"
+      if [[ "$cmaketest" = "false" ]]; then
+	  export basedir="/work/noaa/da/$LOGNAME/gsi"
+      fi
+      export ptmp="${ptmp:-/work/noaa/stmp/$LOGNAME/$ptmpName}"
+
+      export casesdir="/work/noaa/da/rtreadon/CASES/regtest"
+
+      export check_resource="no"
+      export accnt="${accnt:-da-cpu}"
+  ;;      
+  Hera)
+
+    export local_or_default="${local_or_default:-/scratch1/NCEPDEV/da/$LOGNAME}"
+    if [ -d $local_or_default ]; then
+      export noscrub="$local_or_default/noscrub"
+    elif [ -d /scratch1/NCEPDEV/global/$LOGNAME ]; then
+      export noscrub="/scratch1/NCEPDEV/global/$LOGNAME/noscrub"
+     elif [ -d /scratch2/BMC/gsienkf/$LOGNAME ]; then
+      export noscrub="/scratch2/BMC/gsienkf/$LOGNAME"
+    fi
+
+    export group="${group:-global}"
+    export queue="${queue:-batch}"
+    if [[ "$cmaketest" = "false" ]]; then
+      export basedir="/scratch1/NCEPDEV/da/$LOGNAME/git/gsi"
+    fi
+
+    export ptmp="${ptmp:-/scratch1/NCEPDEV/stmp2/$LOGNAME/$ptmpName}"
+
+    export casesdir="/scratch1/NCEPDEV/da/Russ.Treadon/CASES/regtest"
+
+    export check_resource="no"
+    export accnt="${accnt:-da-cpu}"
+
+    #  On Hera, there are no scrubbers to remove old contents from stmp* directories.
+    #  After completion of regression tests, will remove the regression test subdirecories
+    export clean=".false."
+  ;;
+  Jet)
+
+    export noscrub=/lfs1/NESDIS/nesdis-rdo2/$LOGNAME/noscrub
+    export ptmp=/lfs1/NESDIS/nesdis-rdo2/$LOGNAME/ptmp
+    export casesdir="/lfs1/NESDIS/nesdis-rdo2/David.Huber/save/CASES/regtest"
+    export check_resource="no"
+    export accnt="nesdis-rdo2"
+
+    export group="global"
+    export queue="batch"
+    if [[ "$cmaketest" = "false" ]]; then
+      export basedir="/lfs1/NESDIS/nesdis-rdo2/$LOGNAME/save/git/gsi"
+    fi
+
+    #  On Jet, there are no scrubbers to remove old contents from stmp* directories.
+    #  After completion of regression tests, will remove the regression test subdirecories
+    export clean=".true."
+  ;;
+  Discover)
+    if [[ "$cmaketest" = "false" ]]; then
+        echo "Regression tests on Discover need to be run via ctest"
+        exit 1
+    fi
+    export ptmp=$basedir
+    export ptmp=$basedir
+    export noscrub=$basedir
+    export casesdir="/discover/nobackup/projects/gmao/obsdev/wrmccart/NCEP_regression/CASES"
+    export check_resource="no"
+    export accnt="g0613"
+    export queue="compute"
+    export clean=".false."
+  ;;
+  *)
+    echo "Regression tests are not setup on '$machine', ABORT!"
+    exit 1
+  ;;
+esac
+
+# We are dealing with *which* endian files
+export endianness="Big_Endian"
+
+# Paths to tmpdir and savedir base on ptmp
+export tmpdir="$ptmp"
+export savdir="$ptmp"
+
+# Variables with the same values are defined below.
+
+# Default resolution
+export JCAP="62"
+
+# Case Study analysis dates
+export global_adate="2022110900"
+export rtma_adate="2020022420"
+export hwrf_nmm_adate="2012102812"
+export fv3_netcdf_adate="2017030100"
+export rrfs_3denvar_glbens_adate="2021072518"
+
+# Paths for canned case data.
+export global_data="$casesdir/gfs/prod"
+export rtma_obs="$casesdir/regional/rtma_binary/$rtma_adate"
+export rtma_ges="$casesdir/regional/rtma_binary/$rtma_adate"
+export hwrf_nmm_obs="$casesdir/regional/hwrf_nmm/$hwrf_nmm_adate"
+export hwrf_nmm_ges="$casesdir/regional/hwrf_nmm/$hwrf_nmm_adate"
+export fv3_netcdf_obs="$casesdir/regional/fv3_netcdf/$fv3_netcdf_adate"
+export fv3_netcdf_ges="$casesdir/regional/fv3_netcdf/$fv3_netcdf_adate"
+export rrfs_3denvar_glbens_obs="$casesdir/regional/rrfs/$rrfs_3denvar_glbens_adate/obs"
+export rrfs_3denvar_glbens_ges="$casesdir/regional/rrfs/$rrfs_3denvar_glbens_adate/ges"
+export rrfs_3denvar_glbens_ens="$casesdir/regional/rrfs/$rrfs_3denvar_glbens_adate/ens"
+
+# Define type of GPSRO data to be assimilated (refractivity or bending angle)
+export gps_dtype="gps_bnd"
+
+# Regression vfydir
+export regression_vfydir="$noscrub/regression"
+
+# Define debug variable - If you want to run the debug tests, set this variable to .true.  Default is .false.
+export debug=".false."
+
+# Define parameters for global_3dvar, global_4dvar, global_4denvar
+export minimization="lanczos"  # If "lanczos", use sqrtb lanczos minimization algorithm.  Otherwise use "pcgsoi".
+export nhr_obsbin="6"          # Time window for observation binning.  Use "6" for 3d4dvar test.  Otherwise use "1"
+
+# Define parameters for hybrid ensemble option test.
+# (default is set to false, so no hybrid ensemble option test.)
+
+export HYBENS_GLOBAL=".false."
+export ENSEMBLE_SIZE_GLOBAL="10"
+export HYBENS_UV_GLOBAL=".true."
+export BETA_S0_GLOBAL="0.5"
+export HYBENS_HOR_SCALE_GLOBAL="1500"
+export HYBENS_VER_SCALE_GLOBAL="20"
+export GENERATE_ENS_GLOBAL=".true."
+export HYBENS_ANISO_GLOBAL=".false."
+
+export HYBENS_REGIONAL=".false."
+export ENSEMBLE_SIZE_REGIONAL="10"
+export HYBENS_UV_REGIONAL=".true."
+export BETA_S0_REGIONAL="0.5"
+export HYBENS_HOR_SCALE_REGIONAL="1500"
+export HYBENS_VER_SCALE_REGIONAL="20"
+export GENERATE_ENS_REGIONAL=".true."
+export HYBENS_ANISO_REGIONAL=".false."
+export NLON_ENS_REGIONAL="0"
+export NLAT_ENS_REGIONAL="0"
+export JCAP_ENS_REGIONAL="0"
+export JCAP_ENS_TEST_REGIONAL="0"
+
+# Toggle EnKF update code bias correction flag: lupd_satbiasc
+# TRUE  =        compute and update radiance bias correction
+# FALSE = do NOT compute or  update radiance bias correction
+# default is FALSE (as done in NCEP operations)
+export lupd_satbiasc=".false."